The long term goal of this research project will be to characterize a cationic salivary protein currently identified in submaxillary-sublingual (SM-SL) saliva but apparently absent in parotid saliva. Preliminary studies of this cationic protein indicate a pI of 8.3 and a MW of 16,400 daltons. The cationic SM-SL protein (CSP) reacts immunochemically with antisera raised in both the goat and rabbit against human SM-SL saliva. CSP represents 10% of the total SM-SL salivary protein. To date this protein has not been investigated only observed. It is the objective of this study to raise antibodies, and test for cross reactivity with other salivary proteins (parotid and submandibular and minor salivary gland secretions) to develop a procedure for quantitation of the CSP and then examine various clinical groups, i.e., caries resistant vs. caries susceptible, heavy vs. light calculus, heavy vs. light stain formers and saliva of Cystic Fibrosis patients. Also a possible biological role will be established by examining binding to hydroxyapatite of CSP and effects on bacterial membranes.